There is Japanese Unexamined Patent Application Publication No. 6-294854 as a prior art document that discloses a configuration of a sensor chip being a magnetic sensor whose output signal is proportional to current of a measurement subject. This sensor chip is arranged at a busbar through an insulator. The busbar is a conductor through which the current of the measurement subject flows.
Also, a plurality of planar pieces are formed on the surface of the sensor chip. The planar pieces serve as external contacts. These planar pieces are connected to pins integrally formed with the busbar and provided for power feed and output extraction of the sensor chip. Hence, the busbar and the magnetic sensor are integrally formed.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 6-294854.
In the case in which the busbar and the magnetic sensor are integrally formed in the current sensor, a user of the current sensor could not customize the current sensor by selecting a combination of a structure of busbar and a type of magnetic sensor.